Display panel or portion thereof with a transitional graphical user interface



FIG. 1 is a front view of a display panel or portion thereof with a transitional graphical user interface showing a first image in a sequence according to our new design;

FIG. 2 is a front view of a display panel or portion thereof with a transitional graphical user interface showing a second image in the sequence according to our new design;

FIG. 3 is a front view of a display panel or portion thereof with a transitional graphical user interface showing an alternative second image in the sequence according to our new design; and,

FIG. 4 is a front view of a display panel or portion thereof with a transitional graphical user interface showing another alternative second image in the sequence according to our new design.

The appearance of the transitional graphical user interface transitions sequentially between FIGS. 1 and 2 in the first embodiment, FIGS. 1 and 3 in the second embodiment, and FIGS. 1 and 4 in the third embodiment. The process or period in which one image transitions into another forms no part of the claimed design, nor is the order of the drawing figures restrictive of the particular sequence in which the graphical user interface images appear on the display panel.

The broken lines included within the drawings, including the outermost broken line showing a display panel or portion thereof and the other broken lines showing elements of the graphical user interface, form no part of the claimed design. 

CLAIM The ornamental design for a display panel or portion thereof with a transitional graphical user interface, as shown and described. 